options:
        members:
            - openapi_version
            - webhooks
            - state
            - dependency_overrides
            - openapi
            - websocket
            - include_router
            - get
            - put
            - post
            - delete
            - options
            - head
            - patch
            - trace
            - on_event

You can import the `APIRouter` class directly from `fastapi`:

```python
from fastapi import APIRouter
```

::: fastapi.APIRouter
    options:
        members:
            - websocket
            - include_router
            - get
            - put
            - post
            - delete
            - options
            - head
            - patch
            - trace

The original dependency could be used in a *path operation function*, a *path operation decorator* (when you don't use the return value), a `.include_router()` call, etc.

FastAPI will still be able to override it.

///

Then you can reset your overrides (remove them) by setting `app.dependency_overrides` to be an empty `dict`:

```Python

这样一来，**FastAPI** 就会调用覆盖依赖项，不再调用原依赖项。

{* ../../docs_src/dependency_testing/tutorial001_an_py310.py hl[26:27,30] *}

/// tip | 提示

**FastAPI** 应用中的任何位置都可以实现覆盖依赖项。

原依赖项可用于*路径操作函数*、*路径操作装饰器*（不需要返回值时）、`.include_router()` 调用等。

FastAPI 可以覆盖这些位置的依赖项。

///

然后，使用 `app.dependency_overrides` 把覆盖依赖项重置为空**字典**：

```Python
app.dependency_overrides = {}
```

/// tip | 提示

接著 FastAPI 會呼叫這個覆寫，而不是原本的相依。

{* ../../docs_src/dependency_testing/tutorial001_an_py310.py hl[26:27,30] *}

/// tip

你可以為應用程式中任何地方使用到的相依設定覆寫。

原始相依可以用在*路徑操作函式*、*路徑操作裝飾器*（當你不使用其回傳值時）、`.include_router()` 呼叫等。

FastAPI 仍然能夠將其覆寫。

///

然後你可以將 `app.dependency_overrides` 設為空的 `dict` 以重設（移除）所有覆寫：

```Python
app.dependency_overrides = {}
```

/// tip

/// info

`users.router` contains the `APIRouter` inside of the file `app/routers/users.py`.

And `items.router` contains the `APIRouter` inside of the file `app/routers/items.py`.

///

With `app.include_router()` we can add each `APIRouter` to the main `FastAPI` application.

It will include all the routes from that router as part of it.

/// note | Technical Details

Do this:

```python
from fastapi import APIRouter, FastAPI

app = FastAPI()

router = APIRouter(prefix="/items", tags=["items"])


@router.get("/")
async def list_items():
    return []


# In main.py
app.include_router(router)
```

instead of this:

```python

你也可以在*同一*路由器上使用不同的前缀来多次使用 `.include_router()`。

在有些场景这可能有用，例如以不同的前缀公开同一个的 API，比方说 `/api/v1` 和 `/api/latest`。

这是一个你可能并不真正需要的高级用法，但万一你有需要了就能够用上。

## 在另一个 `APIRouter` 中包含一个 `APIRouter` { #include-an-apirouter-in-another }

与在 `FastAPI` 应用程序中包含 `APIRouter` 的方式相同，你也可以在另一个 `APIRouter` 中包含 `APIRouter`，通过：

```Python
router.include_router(other_router)
```

async def inner_strict_post(data: dict):
    return data


@inner_default.post("/items/")
async def inner_default_post(data: dict):
    return data


outer_router.include_router(inner_strict)
outer_router.include_router(inner_default)
app_nested.include_router(outer_router)

client_nested = TestClient(app_nested)


def test_strict_inner_on_lax_app_rejects_no_content_type():

        state.sub_router_startup = True

    @sub_router.on_event("shutdown")
    def sub_router_shutdown() -> None:
        state.sub_router_shutdown = True

    router.include_router(sub_router)
    app.include_router(router)

    assert state.app_startup is False
    assert state.router_startup is False
    assert state.sub_router_startup is False
    assert state.app_shutdown is False